diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py
index f4db7b8a05..2b4faee4c1 100644
--- a/synapse/crypto/keyring.py
+++ b/synapse/crypto/keyring.py
@@ -24,6 +24,8 @@ from synapse.api.errors import SynapseError, Codes
from synapse.util.retryutils import get_retry_limiter
+from synapse.util.async import create_observer
+
from OpenSSL import crypto
import logging
@@ -38,6 +40,8 @@ class Keyring(object):
self.clock = hs.get_clock()
self.hs = hs
+ self.key_downloads = {}
+
@defer.inlineCallbacks
def verify_json_for_server(self, server_name, json_object):
logger.debug("Verifying for %s", server_name)
@@ -97,6 +101,22 @@ class Keyring(object):
defer.returnValue(cached[0])
return
+ download = self.key_downloads.get(server_name)
+
+ if download is None:
+ download = self._get_server_verify_key_impl(server_name, key_ids)
+ self.key_downloads[server_name] = download
+
+ @download.addBoth
+ def callback(ret):
+ del self.key_downloads[server_name]
+ return ret
+
+ r = yield create_observer(download)
+ defer.returnValue(r)
+
+ @defer.inlineCallbacks
+ def _get_server_verify_key_impl(self, server_name, key_ids):
# Try to fetch the key from the remote server.
limiter = yield get_retry_limiter(
diff --git a/synapse/rest/media/v1/base_resource.py b/synapse/rest/media/v1/base_resource.py
index edd4f78024..08c8d75af4 100644
--- a/synapse/rest/media/v1/base_resource.py
+++ b/synapse/rest/media/v1/base_resource.py
@@ -25,6 +25,8 @@ from twisted.internet import defer
from twisted.web.resource import Resource
from twisted.protocols.basic import FileSender
+from synapse.util.async import create_observer
+
import os
import logging
@@ -87,7 +89,7 @@ class BaseMediaResource(Resource):
def callback(media_info):
del self.downloads[key]
return media_info
- return download
+ return create_observer(download)
@defer.inlineCallbacks
def _get_remote_media_impl(self, server_name, media_id):
diff --git a/synapse/util/async.py b/synapse/util/async.py
index c4fe5d522f..d8febdb90c 100644
--- a/synapse/util/async.py
+++ b/synapse/util/async.py
@@ -32,3 +32,22 @@ def run_on_reactor():
iteration of the main loop
"""
return sleep(0)
+
+
+def create_observer(deferred):
+ """Creates a deferred that observes the result or failure of the given
+ deferred *without* affecting the given deferred.
+ """
+ d = defer.Deferred()
+
+ def callback(r):
+ d.callback(r)
+ return r
+
+ def errback(f):
+ d.errback(f)
+ return f
+
+ deferred.addCallbacks(callback, errback)
+
+ return d
|
